RAID5工作原理图解及特点分析

5: Independent Data disks with distributed parity blocks

Characteristics/Advantages

1. Highest Read data transaction rate

2. Medium Write data transaction rate

3. Low ratio of ECC (Parity) disks to data disks means high efficiency

4. Good aggregate transfer rate

Disadvantages

1. Disk failure has a medium impact on throughput

2. Most complex controller design

3. Difficult to rebuild in the event of a disk failure (as compared to level 1)

4. Individual block data transfer rate same as single disk

Recommended Applications

1. File and Application servers

2. Database servers

3. WWW, E-mail, and News servers

4. Intranet servers

5. Most versatile level

Each entire data block is written on a data disk; parity for blocks in the same rank is generated on Writes, recorded in a distributed location and checked on Reads.

Level 5 requires a minimum of 3 drives to implement